When calculating voltage drop for long runs, the choice between solid and stranded conductors of equal cross-section:

When calculating voltage drop for long runs, the choice between solid and stranded conductors of equal cross-section:

• A. Significantly changes the resistance
• B. Has no effect on resistance
• C. Affects only the insulation rating
• D. Higher for stranded due to skin effect at low frequencies

Answer: (B)

The main idea is that voltage drop depends on resistance, which for a given material and length is set by resistivity, length, and cross-sectional area. If two conductors are made of the same material and have the same total cross-section, their resistance per unit length is basically the same, whether one is solid or stranded. At the frequencies typical for power systems (50/60 Hz), current distributes across the entire cross-section, so skin effect is negligible and doesn’t make stranded conductors more or less resistive than solid ones of equal area. Any tiny differences due to how tightly strands are packed or contact between strands are usually ignored in standard voltage-drop calculations. The insulation rating isn’t about resistance in this context, and skin effect is a high-frequency phenomenon, not a factor at low frequencies. So the practical result is that the resistance is essentially unchanged by choosing solid versus stranded conductors of the same cross-section.

The main idea is that voltage drop depends on resistance, which for a given material and length is set by resistivity, length, and cross-sectional area. If two conductors are made of the same material and have the same total cross-section, their resistance per unit length is basically the same, whether one is solid or stranded. At the frequencies typical for power systems (50/60 Hz), current distributes across the entire cross-section, so skin effect is negligible and doesn’t make stranded conductors more or less resistive than solid ones of equal area. Any tiny differences due to how tightly strands are packed or contact between strands are usually ignored in standard voltage-drop calculations. The insulation rating isn’t about resistance in this context, and skin effect is a high-frequency phenomenon, not a factor at low frequencies. So the practical result is that the resistance is essentially unchanged by choosing solid versus stranded conductors of the same cross-section.